J. B. Hatcher — Ceratops Beds of Wyoming. 137 



Converse county. The creeks mentioned in this paper will 

 be found on any good map of Wyoming. 



Description of the Deposits. 



The Ceratops beds are made up of alternating sandstones, 

 shales, and lignites, with occasional local deposits of limestones 

 and marls. The different strata of the series are not always 

 continuous, a stratum of sandstone giving place to one of 

 shales and vice versa. This is especially true of the upper 

 two-thirds of the beds. The lack of continuity in the dif- 

 ferent strata has rendered it well nigh impossible to establish 

 any definite horizons in the upper members of the series. All 

 the deposits of the Ceratops beds of this region bear evidence 

 of having been laid down in fresh-waters. Among the inver- 

 tebrate fossils found in them, only fresh-water forms are 

 known. There is no evidence that marine or brackish-waters 

 have ever had access to this region since the recession of the 

 former at the close of the Fox Hills period. 



The sandstones largely predominate in the lower members 

 of the beds. They are always fine-grained, massive to well- 

 stratified, and nearly white to yellowish brown in color. They 

 are occasionally compact and hard, but for the most part quite 

 soft and friable. They are composed of sharp, angular grains 

 of quartz with some clay and mica, the whole being loosely 

 cemented together with carbonate of lime. Almost every- 

 where in the sandstones are numerous concretions of varying 

 size and shape. Some are almost perfect spheres and vary 

 from the size of a marble to 18 or 20 feet in diameter. Others 

 are from a few inches to several feet in transverse diameter 

 and sometimes several hundred feet in length, a cross section 

 forming a nearly perfect circle. Others still are very irregu- 

 lar in form. These concretions usually show no concentric 

 structure, and while they sometimes enclose foreign objects, as 

 a Triceratops skull or a single bone as a nucleus, they are for 

 the most part simply centers of solidification and not true con- 

 cretions. This is frequently shown by the cross-bedding in 

 them, so often seen in the sandstones themselves. 



The shales are almost entirely wanting in the lower 400 feet 

 of the Ceratops beds, but they are well represented in the suc- 

 ceeding series. They are quite soft and loosely compacted, 

 composed mostly of clay with more or less sand in places. 

 The prevailing color is dark brown, but they are sometimes 

 red or bluish. They are well stratified and finely laminated, 

 and contain occasional limestone concretions enclosing numer- 

 ous invertebrates. 



